Lifting equipment

Abstract

To provide a hanging tool capable of being manually inserted in a hanging object and removed from the hanging object and easily attached to / removed from the hanging object.SOLUTION: A hanging tool 100 includes a first link member 1 and a second link member 2 rotatably supported by a first connection shaft 51, a third link member 3 rotatably supported to the first link member 1 by a second connection shaft 52, and a fourth link member 4 rotatably supported to the second link member 2 by a third connection shaft 53 and rotatably supported to the third link member 3 by a fourth connection shaft 54. The third link member 3 has a first hook part 31. The fourth link member 4 has a second hook part 41. The first hook part 31 has a first holding part 32 which can push the first hook part 31 in the direction of the second hook part 41. The second hook part 41 has a second holding part 42 which can push the second hook part 41 in the direction of the first hook part 31.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lifting tool that is attached to a lifting device such as a crane and that is attached to and detached from an object to be lifted in order to lift the object. [Background technology]

[0002] When a crane is used to transport a heavy object, the object is suspended via a hoisting device attached to the crane's wire. Among such hoisting devices, there is one that hooks the object using the force with which the crane lifts the object. When the crane lifts the hoisting device, with its tip positioned within the hoisting hole of the object, a link mechanism moves the tips of the hoisting devices in directions away from each other. The moved tips of the hoisting devices hook onto the object within the hoisting hole. Patent Document 1 describes an example of a hoisting device that allows the tip of the hoisting device to be manually operated.

[0003] Patent Document 1 describes a lifting device for lifting a reel having a vertical cylindrical reel body around which a wire is wound. Specifically, the lifting device disclosed in Patent Document 1 has a pair of arc-shaped pieces pivotally connected in an X-shape. Each lower end of the arc-shaped pieces has a locking portion that engages with a protruding edge of the opening of the reel. Furthermore, one end of an upper link piece is rotatably connected to the upper end of each of the arc-shaped pieces. Similarly, the other ends of the upper link pieces are rotatably connected to each other. When the lifting device is lifted by the link mechanism consisting of the two arc-shaped pieces and the two upper link pieces, the distance between the lower ends of the two arc-shaped pieces increases. This allows the reel to be lifted without falling off. Furthermore, the lifting device has a finger hook for narrowing the distance between the lower ends of the two arc-shaped pieces. The lifting device can bring the lower ends of the two arc-shaped pieces closer together by pulling the finger hook outward. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-212090 Summary of the Invention [Problem to be solved by the invention]

[0005] When hooking the lifting device disclosed in Patent Document 1 onto the reel, the operator must use both hands to pull both of the finger hooks provided on each of the arc-shaped pieces. In other words, the operator must adjust the lower end of the lifting device to a position where it can be inserted into the reel while pulling the finger hooks with both hands. Therefore, when a hole or the like for inserting the lifting tool in the object to be lifted is small compared to the lower end of the lifting tool, the operation of inserting the lower end of the lifting tool into the hole or the like is cumbersome.

[0006] The present invention aims to provide a lifting device that can be easily attached to and detached from an object to be lifted, and that can apply a force to the object to hold it by lifting it. [Means for solving the problem]

[0007] A lifting device according to one embodiment of the present invention is a lifting device that is attached to a lifting device and detached from an object to be lifted in order to lift the object. The lifting device includes a connecting member, a first link member, a second link member, a third link member, and a fourth link member. The connecting member is attached to the lifting device. One end of each of the first link member and the second link member is rotatably supported on the connecting member by a first connecting shaft. One end of the third link member is rotatably supported on the other end of the first link member by a second connecting shaft positioned parallel to the first connecting shaft. One end of the fourth link member is rotatably supported on the other end of the second link member by a third connecting shaft positioned parallel to the first connecting shaft. The other end of the third link member and the other end of the fourth link member are rotatably connected by a fourth connecting shaft positioned parallel to the first connecting shaft.

[0008] The third link member and the fourth link member are positioned so as to be symmetrical with respect to an imaginary line perpendicular to the axis of the first connecting shaft and the axis of the fourth connecting shaft. When the second connecting shaft and the third connecting shaft are positioned on either side of the imaginary line, the third link member has, at its other end, a first hook portion that is closer to the second connecting shaft than the imaginary line as viewed in the axial direction of the first connecting shaft and extends in a direction away from the second connecting shaft. When the second connecting shaft and the third connecting shaft are positioned on either side of the imaginary line, the fourth link member has, at its other end, a second hook portion that is closer to the third connecting shaft than the imaginary line as viewed in the axial direction of the first connecting shaft and extends in a direction away from the third connecting shaft. The first hook portion has a first grip portion that protrudes toward the second connecting shaft as viewed in the axial direction of the first connecting shaft and is capable of pressing the first hook portion toward the second hook portion, and a first protrusion that holds the object to be lifted further distal than the first grip portion. The second hook portion protrudes toward the third connecting shaft when viewed in the axial direction of the first connecting shaft and has a second gripping portion that can press the second hook portion toward the first hook portion, and a second convex portion that holds the object to be lifted further tip-side than the second gripping portion. [Effects of the Invention]

[0009] By pressing the first gripping portion and the second gripping portion toward each other, the first hook portion and the second hook portion rotate toward each other around the fourth connecting shaft as a rotation axis. This allows the first hook portion and the second hook portion of the hoisting tool to be easily inserted into and removed from the object to be hoisted simply by holding the first gripping portion and the second gripping portion with one hand. Furthermore, in the hoisting tool, rotation of the first link member and the second link member about the first connecting shaft as a rotation axis causes the third link member and the fourth link member to rotate toward each other around the fourth connecting shaft as a rotation axis. Accordingly, the first hook portion and the second hook portion of the third link member and the fourth link member rotate away from each other around the fourth connecting shaft as a rotation axis. This allows a force to be applied to the object to be hoisted, holding the object in a lifted state, by a lifting operation. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a view of a suspender according to an embodiment as viewed from the axial direction. [Figure 2] FIG. 2 is a view of the sling shown in FIG. 1 as seen from the right side. [Figure 3] FIG. 3 is a diagram illustrating an example of a sling according to an embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of a suspender according to an embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of a suspender according to an embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of a sling according to an embodiment. [Figure 7] FIG. 7 is a diagram showing an example of an object to be lifted. DETAILED DESCRIPTION OF THE INVENTION

[0011] (hanging device) An overview of a hoisting tool 100 according to an embodiment of the present invention will be described using Figures 1 to 7. The hoisting tool 100 is used when hoisting an object to be hoisted 200. To hoist the object to be hoisted 200, the hoisting tool 100 is connected to a hoisting device (not shown). The hoisting device is, for example, a crane. As shown in Figure 6, a wire 301 of the hoisting device is connected to the hoisting tool 100.

[0012] FIG. 7 shows an example of a lifted object 200. The lifted object 200 shown in FIG. 7 is, for example, a type of earth retaining material such as a shelf pile. The lifted object 200 has at least one insertion hole 201 drilled in its side wall. The insertion hole 201 is a hole into which the lifting tool 100 is inserted. In FIG. 7, only one of the multiple insertion holes 201 is labeled. The sizes of the insertion hole 201, such as the inner diameter and depth, are standardized. The lifted object 200 is lifted via the lifting tool 100.

[0013] The sling device 100 is made of, for example, metal. As shown in Figures 1 and 2, the sling device 100 includes a link mechanism 10, a connecting member 60, and an elastic member 70.

[0014] (Connecting member) As shown in FIGS. 2 and 6, the connecting member 60 is a member for connecting the wire 301. For example, the connecting member 60 is a shackle. The connecting member 60 has a pair of legs 60a at both ends of a U-shape. Each leg 60a has a connection hole (not shown). A first connecting shaft 51 (described later) is inserted into each leg 60a.

[0015] (Link mechanism) As shown in Figures 1 to 6, the link mechanism 10 includes a first link member 1, a second link member 2, a third link member 3, a fourth link member 4, a first connecting shaft 51, a second connecting shaft 52, a third connecting shaft 53, and a fourth connecting shaft 54.

[0016] The first connecting shaft 51, the second connecting shaft 52, the third connecting shaft 53, and the fourth connecting shaft 54 are shafts that connect the link members of the link mechanism 10. The first connecting shaft 51, the second connecting shaft 52, the third connecting shaft 53, and the fourth connecting shaft 54 are positioned in parallel. In other words, the axes (center axes) of the first connecting shaft 51, the second connecting shaft 52, the third connecting shaft 53, and the fourth connecting shaft 54 are parallel to each other.

[0017] (First link member) The first link member 1 is a substantially rectangular plate material and has a through hole for a first connecting shaft 51 and a through hole for a second connecting shaft 52 (not shown) aligned in the longitudinal direction.

[0018] The first connecting shaft 51 is inserted into the through hole for the first connecting shaft 51 of the first link member 1. One end of the first link member 1 and the connecting member 60 are rotatable around the first connecting shaft 51 as a rotation axis. One end of the first link member 1 is rotatably supported by the first connecting shaft 51. The second connecting shaft 52 is inserted into the through hole for the second connecting shaft 52 of the first link member 1. As a result, the other end of the first link member 1 is rotatable around the second connecting shaft 52 as a rotation axis. The first connecting shaft 51 and the second connecting shaft 52 are positioned with a predetermined distance A1 between them.

[0019] (Second link member) The second link member 2 is a substantially rectangular plate material and has a through hole for the first connecting shaft 51 and a through hole for the third connecting shaft 53, not shown, aligned in the longitudinal direction.

[0020] The first connecting shaft 51 is inserted into the through hole for the first connecting shaft 51 of the second link member 2. One end of the second link member 2 is rotatable around the first connecting shaft 51 as a rotation axis. The first connecting shaft 51 is inserted into both the through hole at one end of the first link member 1 and the through hole at one end of the second link member 2. As shown in FIG. 1 , when viewed in the axial direction of the first connecting shaft 51, one end of the second link member 2 overlaps one end of the first link member 1.

[0021] The third connecting shaft 53 is inserted into the through hole for the third connecting shaft 53 of the second link member 2. This allows the other end of the second link member 2 to rotate around the third connecting shaft 53 as a rotation axis. The first connecting shaft 51 and the third connecting shaft 53 are positioned with a predetermined distance A2 between them.

[0022] (Third link member and fourth link member) The third link member 3 is a plate member having a first hook portion 31. The third link member 3 has a through hole for a second connecting shaft 52 (not shown) at an end portion. The third link member 3 also has a through hole for a fourth connecting shaft 54.

[0023] The second connecting shaft 52 is inserted into the through hole for the second connecting shaft 52 of the third link member 3. The third link member 3 is rotatable around the second connecting shaft 52 as a rotation axis. When viewed in the axial direction of the first connecting shaft 51, the other end of the first link member 1 overlaps with the through hole for the second connecting shaft 52 of the third link member 3. The fourth connecting shaft 54 is inserted into the through hole for the fourth connecting shaft 54 of the third link member 3. The third link member 3 is rotatable around the fourth connecting shaft 54 as a rotation axis. The second connecting shaft 52 and the fourth connecting shaft 54 are positioned with a predetermined distance A3 between them.

[0024] The fourth link member 4 is a plate member having a second hook portion 41. The fourth link member 4 has a through hole for a third connecting shaft 53 (not shown) at one end. The fourth link member 4 also has a through hole for a fourth connecting shaft 54.

[0025] The third connecting shaft 53 is inserted into the through hole of the fourth link member 4 for the third connecting shaft 53. The fourth link member 4 is rotatable around the third connecting shaft 53 as a rotation axis. When viewed in the axial direction of the first connecting shaft 51, the other end of the second link member 2 overlaps with one end of the fourth link member 4. The fourth connecting shaft 54 is inserted into the through hole of the fourth link member 4 for the fourth connecting shaft 54. The fourth link member 4 is rotatable around the fourth connecting shaft 54 as a rotation axis. The third connecting shaft 53 and the fourth connecting shaft 54 are positioned with a predetermined distance A4 between them.

[0026] In the following description, a line perpendicular to the axis of the first connecting shaft 51 and the axis of the fourth connecting shaft 54 will be referred to as an imaginary line VL.

[0027] The distance A1, which is the axial distance between the first connecting shaft 51 and the second connecting shaft 52, is equal to the distance A2, which is the axial distance between the first connecting shaft 51 and the third connecting shaft 53. Furthermore, the distance A3, which is the axial distance between the fourth connecting shaft 54 and the second connecting shaft 52, is equal to the distance A4, which is the axial distance between the fourth connecting shaft 54 and the third connecting shaft 53. Therefore, when the second connecting shaft 52 and the third connecting shaft 53 are arranged line-symmetrically with respect to the imaginary line VL, the first link member 1 and the second link member 2 are positioned line-symmetrically with respect to the imaginary line VL when viewed in the axial direction of the first connecting shaft 51. Furthermore, the third link member 3 and the fourth link member 4 are positioned line-symmetrically with respect to the imaginary line VL when viewed in the axial direction of the first connecting shaft 51. The thickness of the first link member 1, the second link member 2, the third link member 3, and the fourth link member 4 in the axial direction of the first connecting shaft 51 is equal.

[0028] Next, the details of the first hook portion 31 will be described. The first hook portion 31 is provided on the third link member 3. The first hook portion 31 is inserted into the insertion hole 201 of the object to be lifted 200 and hooks onto the object to be lifted 200. The first hook portion 31 is located near the fourth connecting shaft 54 of the third link member 3. As shown in FIG. 1 , when the second connecting shaft 52 and the third connecting shaft 53 are positioned on either side of the imaginary line VL, the first hook portion 31 extends from the other end near the fourth connecting shaft 54 in a direction perpendicular to the axis of the fourth connecting shaft 54 when viewed in the axial direction of the first connecting shaft 51, and in a direction away from the second connecting shaft 52 and closer to the second connecting shaft 52 than the imaginary line VL. The first hook portion 31 has a first grip portion 32 and a first protrusion 33.

[0029] The first grip portion 32 is a portion that an operator holds with his or her hand. The first grip portion 32 is located at the base end of the first hook portion 31, near the fourth connecting shaft 54. When viewed in the axial direction of the first connecting shaft 51, the first grip portion 32 protrudes toward the second connecting shaft 52. On the side surface of the first grip portion 32 facing the second connecting shaft 52, the portion that comes into contact with the fingers is recessed toward the third connecting shaft 53.

[0030] The first protrusion 33 is a portion that is hooked onto the object to be lifted 200 when lifting the object to be lifted 200. The first protrusion 33 is located at the tip of the first hook portion 31. That is, the first protrusion 33 is located closer to the tip of the first hook portion 31 than the first gripping portion 32. The first protrusion 33 also protrudes toward the second connecting shaft 52 of the first hook portion 31 when viewed in the axial direction of the first connecting shaft 51. The side surface of the first protrusion 33 on the first gripping portion 32 side is located farther away from the side surface of the first gripping portion 32 on the first protrusion 33 side than the thickness L0 of the object to be lifted 200.

[0031] 1, the first stopper 34 is provided on the first grip portion 32. The first stopper 34 protrudes toward the second hook portion 41 in the axial direction of the first connecting shaft 51. The first stopper 34 comes into contact with the second hook portion 41 at a predetermined position to restrict the rotation of the second hook portion 41.

[0032] Next, the second hook portion 41 will be described in detail. The second hook portion 41 is provided on the fourth link member 4. The second hook portion 41 is inserted into the insertion hole 201 of the object to be lifted 200 and hooks onto the object to be lifted 200. The second hook portion 41 is located near the fourth connecting shaft 54 of the fourth link member 4. As shown in FIG. 1 , when the second connecting shaft 52 and the third connecting shaft 53 are positioned on either side of the imaginary line VL, the second hook portion 41 extends from the other end near the fourth connecting shaft 54 in a direction perpendicular to the axis of the fourth connecting shaft 54 when viewed in the axial direction of the first connecting shaft 51, and in a direction away from the third connecting shaft 53 and closer to the third connecting shaft 53 than the imaginary line VL. The second hook portion 41 has a second grip portion 42 and a second protrusion 43.

[0033] The second grip portion 42 is a portion that an operator holds with his or her hand. The second grip portion 42 is located at the base end of the second hook portion 41, which is in the vicinity of the fourth connecting shaft 54. The second grip portion 42 protrudes toward the third connecting shaft 53 when viewed in the axial direction of the first connecting shaft 51. On the side surface of the second grip portion 42 facing the third connecting shaft 53, the portion that comes into contact with the fingers is recessed toward the second connecting shaft 52.

[0034] The second protrusion 43 is a portion that is hooked onto the object to be lifted 200 when the object to be lifted 200 is lifted. The second protrusion 43 is located at the tip of the second hook portion 41. That is, the second protrusion 43 is located closer to the tip of the second hook portion 41 than the second gripping portion 42. The second protrusion 43 also protrudes toward the third connecting shaft 53 of the second hook portion 41 when viewed in the axial direction of the first connecting shaft 51. The side surface of the second protrusion 43 on the second gripping portion 42 side is located farther away from the side surface of the second gripping portion 42 on the second protrusion 43 side than the thickness L0 of the object to be lifted 200.

[0035] 1, the second stopper 44 is provided on the second grip portion 42. The second stopper 44 protrudes toward the first hook portion 31 in the axial direction of the first connecting shaft 51. The second stopper 44 comes into contact with the first hook portion 31 at a predetermined position to restrict the rotation of the first hook portion 31.

[0036] (elastic member) The elastic member 70 biases the second connecting shaft 52 and the third connecting shaft 53 in a direction that brings them closer together. The elastic member 70 is located between the second connecting shaft 52 and the third connecting shaft 53. One end of the elastic member 70 is attached to the second connecting shaft 52. The other end of the elastic member 70 is attached to the third connecting shaft 53. For example, the elastic member 70 is a tension spring. When the first gripping portion 32 and the second gripping portion 42 are not gripped, the elastic member 70 is in its most contracted state.

[0037] (Installation of hanging equipment) An example of attaching the hoisting tool 100 to the object to be lifted 200 will be described using Fig. 1 and Fig. 3 to Fig. 6. Fig. 3 shows an example of the hoisting tool 100 when inserted into the insertion hole 201 of the object to be lifted 200. Fig. 4 shows an example of the state in which the hoisting tool 100 has been inserted into the insertion hole 201 of the object to be lifted 200. Fig. 5 shows an example of the hoisting tool 100 in a state in which the fingers have been released after insertion into the insertion hole 201. Fig. 6 is a diagram showing an example of the hoisting tool 100 in a state in which the object to be lifted 200 is being lifted using the wire 301.

[0038] First, a description will be given of the state in which sling device 100 is not being lifted or gripped. Fig. 1 shows an example of sling device 100 in an ungrasped state. Second connecting shaft 52 and third connecting shaft 53 are positioned closest to each other due to contraction of elastic member 70.

[0039] 1, when the second connecting shaft 52 and the third connecting shaft 53 move in a direction toward each other, the first link member 1 and the second link member 2 rotate around the first connecting shaft 51 as a rotation axis in a direction toward each other. Also, the third link member 3 connected to the first link member 1 via the second connecting shaft 52 rotates around the fourth connecting shaft 54 as a rotation axis in a direction toward the imaginary line VL. The fourth link member 4 connected to the second link member 2 via the third connecting shaft 53 rotates around the fourth connecting shaft 54 as a rotation axis in a direction toward the imaginary line VL.

[0040] As a result, the first hook portion 31, which is located closer to the second connecting shaft 52 than the imaginary line VL, rotates around the fourth connecting shaft 54 as its axis of rotation in a direction away from the imaginary line VL. Also, the second hook portion 41, which is located closer to the third connecting shaft 53 than the imaginary line VL, moves around the fourth connecting shaft 54 as its axis of rotation in a direction away from the imaginary line VL. In other words, the first hook portion 31 and the second hook portion 41 move in directions away from each other.

[0041] Next, the operation of the hoisting tool 100 when inserting the tip of the hoisting tool 100 into the insertion hole 201 of the object to be lifted 200 will be described. When inserting the tip of the hoisting tool 100 into the insertion hole 201 of the object to be lifted 200, the first hook portion 31 and the second hook portion 41 must be brought close to each other and positioned so that they can be inserted into the insertion hole 201 of the object to be lifted 200.

[0042] As shown in Fig. 3, when the worker brings the first hook portion 31 and the second hook portion 41 closer together, the worker grips the first grip portion 32 of the third link member 3 and the second grip portion 42 of the fourth link member 4 in a direction that brings them closer to each other. The outline arrows in Fig. 3 show an example of the direction in which the first grip portion 32 and the second grip portion 42 are pressed against each other.

[0043] When the first gripping portion 32 and the second gripping portion 42 are pressed with one hand, the first hook portion 31 rotates in a direction approaching the imaginary line VL around the fourth connecting shaft 54. The second hook portion 41 rotates in a direction approaching the imaginary line VL around the fourth connecting shaft 54.

[0044] When the first hook portion 31 rotates until it contacts the second stopper 44, the first protrusion 33 of the first hook portion 31 overlaps the second protrusion 43 of the second hook portion 41 when viewed in the axial direction of the first connecting shaft 51. At this time, the entirety of one of the first protrusion 33 and the second protrusion 43 overlaps the other. In other words, the first stopper 34 and the second stopper 44 maintain a state in which the entirety of one of the first protrusion 33 and the second protrusion 43 overlaps the other by the gripping operation between the first gripping portion 32 and the second gripping portion 42.

[0045] As a result, in the lifting device 100, the portion of the first hook portion 31 more distal than the first gripping portion 32 and the portion of the second hook portion 41 more distal than the second gripping portion 42, which are inserted into the insertion hole 201 of the lifting target 200, have the narrowest width L1 in a direction perpendicular to the imaginary line VL between the portion furthest from the imaginary line VL to the second connecting shaft 52 and the portion furthest from the imaginary line VL to the third connecting shaft 53, as viewed in the axial direction of the first connecting shaft 51. In this embodiment, the width L1 when the first convex portion 33 of the first hook portion 31 and the second convex portion 43 of the second hook portion 41 overlap is smaller than the diameter D1 of the insertion hole 201. As a result, the portion of the first hook portion 31 more distal than the first gripping portion 32 and the portion of the second hook portion 41 more distal than the second gripping portion 42 can be inserted into the insertion hole 201.

[0046] Furthermore, when the first hook portion 31 contacts the second stopper 44 or the second hook portion 41 contacts the first stopper 34, the width L2 of the first gripping portion 32 and the second gripping portion 42 of the sling device 100 in the direction perpendicular to the imaginary line VL between the portion furthest from the imaginary line VL to the second connecting shaft 52 side and the portion furthest from the imaginary line VL to the third connecting shaft 53 side, as viewed in the axial direction of the first connecting shaft 51, is larger than the diameter D1 of the insertion hole 201. Therefore, the first gripping portion 32 and the second gripping portion 42 cannot be inserted into the insertion hole 201. As a result, the position of the first hook portion 31 and the second hook portion 41 of the sling device 100 in the insertion direction when inserted into the insertion hole 201 is determined by the first gripping portion 32 and the second gripping portion 42.

[0047] Furthermore, when the third link member 3 and the second stopper 44 are in contact, or when the fourth link member 4 and the first stopper 34 are in contact, the portion of the first gripping portion 32 that comes into contact with the fingers protrudes toward the second connecting shaft 52 beyond the side surface of the second hook portion 41 that faces the second connecting shaft 52. Similarly, the portion of the second gripping portion 42 that comes into contact with the fingers protrudes toward the third connecting shaft 53 beyond the side surface of the first hook portion 31 that faces the third connecting shaft 53. Therefore, when the first gripping portion 32 and the second gripping portion 42 of the sling device 100 are held with one hand, the fingers will not be pinched between the third link member 3 and the fourth link member 4.

[0048] Furthermore, when the third link member 3 and the second stopper 44 are in contact, or the fourth link member 4 and the first stopper 34 are in contact, the side surface of the first hook portion 31 facing the third connecting shaft 53, which is further distal than the first gripping portion 32, and the side surface of the second hook portion 41 facing the second connecting shaft 52, which is further distal than the second gripping portion 42, are parallel to each other. The portions of the first hook portion 31 and the second hook portion 41 that are inserted into the insertion hole 201 have a constant width relative to the insertion hole 201, making them easy to insert into the insertion hole 201.

[0049] As shown in FIG. 4 , with either the first protrusion 33 of the first hook portion 31 or the second protrusion 43 of the second hook portion 41 fully overlapping the other, the worker inserts the portion of the first hook portion 31 further distal than the first gripping portion 32 and the portion of the second hook portion 41 further distal than the second gripping portion 42 into the insertion hole 201 of the object to be lifted 200. The lifting tool 100 is inserted into the insertion hole 201 until the first gripping portion 32 and the second gripping portion 42 come into contact with the object to be lifted 200. At this time, the first protrusion 33 and the second protrusion 43 of the lifting tool 100 pass through the insertion hole 201 and are positioned outside the insertion hole 201. In other words, the object to be lifted 200 is positioned between the first gripping portion 32, the second gripping portion 42, and the first protrusion 33 and the second protrusion 43.

[0050] As shown in Figure 5, the worker stops gripping the sling device 100 in order to connect the sling device 100 to the object to be lifted 200. When the worker releases his / her hands from the first gripping portion 32 and the second gripping portion 42, the second connecting shaft 52 and the third connecting shaft 53 of the sling device 100 are brought closer together by the elastic member 70. The first hook portion 31 of the third link member 3 and the second hook portion 41 of the fourth link member 4 rotate in directions away from each other with the fourth connecting shaft 54 as the rotation axis.

[0051] First hook portion 31 moves in a direction approaching the inner circumferential surface of insertion hole 201. Similarly, second hook portion 41 moves in a direction approaching the inner circumferential surface of insertion hole 201. As a result, in lifting device 100, a part of object to be lifted 200, including the inner circumferential surface of insertion hole 201, gets between first gripping portion 32 and first convex portion 33 of first hook portion 31 and between second gripping portion 42 and second convex portion 43 of second hook portion 41.

[0052] As shown in FIG. 6 , the hoisting device 100 is lifted by a lifting device with the first hook portion 31 and the second hook portion 41 in contact with the object to be lifted 200. The hoisting device pulls the connecting member 60 up vertically away from the object to be lifted 200 (see the dashed arrow). That is, a force acts on the hoisting device 100 in a direction that moves the first connecting shaft 51 away from the fourth connecting shaft 54. Furthermore, a reaction force acts on the hoisting device 100 due to the gravity of the object to be lifted 200 in a direction that moves the fourth connecting shaft 54 away from the first connecting shaft 51. In the hoisting device 100, the force applied to the first connecting shaft 51 and the fourth connecting shaft 54 is transmitted to the first link member 1, the second link member 2, the third link member 3, and the fourth link member 4.

[0053] A force is applied to the first link member 1 and the second link member 2, causing them to rotate about the first connecting shaft 51 as a rotation axis in a direction approaching the imaginary line VL. A force is applied to the third link member 3 and the fourth link member 4, which are respectively connected to the first link member 1 and the second link member 2, causing them to rotate about the fourth connecting shaft 54 as a rotation axis in a direction approaching the imaginary line VL. As a result, a force is applied to the first hook portion 31 of the third link member 3, causing it to rotate about the fourth connecting shaft 54 as a rotation axis toward the second connecting shaft 52, that is, in a direction away from the imaginary line VL. A force is applied to the second hook portion 41 of the fourth link member 4, causing it to rotate about the fourth connecting shaft 54 as a rotation axis toward the third connecting shaft 53, that is, in a direction away from the imaginary line VL.

[0054] The first hook portion 31 is pressed against the object to be lifted 200 by a force of rotation about the fourth connecting shaft 54 as the rotation axis. Similarly, the second hook portion 41 is pressed against the object to be lifted 200. In other words, while the lifting device is lifting the object to be lifted 200, the first hook portion 31 and the second hook portion 41 of the lifting tool 100 are pressed against a part of the object to be lifted 200, including the inner circumferential surface of the insertion hole 201. The lifting tool 100 supports the object to be lifted 200 with the first convex portion 33 and the second convex portion 43. In this way, the lifting tool 100 utilizes the weight of the object to be lifted 200 to make it difficult for the first hook portion 31 and the second hook portion 41 to come off the object to be lifted 200.

[0055] (Removing the lifting device) An example of detaching the hoisting device 100 will be described with reference to Fig. 3. When the movement of the lifted object 200 is completed, the hoisting device 100 is detached from the lifted object 200.

[0056] The worker performs a gripping operation on the first gripping portion 32 and the second gripping portion 42 of the sling device 100. When the first gripping portion 32 and the second gripping portion 42 of the sling device 100 are gripped, the first convex portion 33 of the first hook portion 31 and the second convex portion 43 of the second hook portion 41 rotate in a direction approaching the imaginary line VL.

[0057] The first hook portion 31 and the second hook portion 41 are pressed until the first hook portion 31 contacts the second stopper 44, or the second hook portion 41 contacts the first stopper 34. That is, the first hook portion 31 and the second hook portion 41 are pressed until either the first protrusion 33 or the second protrusion 43 entirely overlaps the other. This moves the first hook portion 31 and the second hook portion 41 to a position where they can be removed from the insertion hole 201. The worker detaches the lifting device 100 from the object to be lifted 200 by moving the lifting device 100 in a direction to remove it from the insertion hole 201 while holding it with one hand.

[0058] In this way, the lifting device 100 is attached to a lifting device and is detachable from the object to be lifted 200 in order to lift the object to be lifted 200. The lifting device 100 has a connecting member 60, a first link member 1, a second link member 2, a third link member 3, and a fourth link member 4. The connecting member 60 is attached to the lifting device. One end of the first link member 1 and the second link member 2 is rotatably supported to the connecting member 60 by a first connecting shaft 51. One end of the third link member 3 is rotatably supported to the other end of the first link member 1 by a second connecting shaft 52 positioned parallel to the first connecting shaft 51. One end of the fourth link member 4 is rotatably supported to the other end of the second link member 2 by a third connecting shaft 53 positioned parallel to the first connecting shaft 51. The other end of the third link member 3 and the other end of the fourth link member 4 are rotatably connected by a fourth connecting shaft 54 positioned parallel to the first connecting shaft 51. The third link member 3 and the fourth link member 4 are positioned so as to be symmetrical with each other with respect to a virtual line VL that is perpendicular to the axis of the first connecting shaft 51 and the axis of the fourth connecting shaft 54.

[0059] The third link member 3 has, at its other end, a first hook portion 31 that is closer to the second connecting shaft 52 than the imaginary line VL when viewed in the axial direction of the first connecting shaft 51 and extends in a direction away from the second connecting shaft 52 when the second connecting shaft 52 and the third connecting shaft 53 are at their closest. The fourth link member 4 has, at its other end, a second hook portion 41 that is closer to the third connecting shaft 53 than the imaginary line VL when viewed in the axial direction of the first connecting shaft 51 and extends in a direction away from the third connecting shaft 53 when viewed in the axial direction of the first connecting shaft 51. The first hook portion 31 has a first gripping portion 32 that protrudes toward the second connecting shaft 52 when viewed in the axial direction of the first connecting shaft 51 and can press the first hook portion 31 toward the second hook portion 41, and a first protrusion 33 that holds the object to be lifted 200 distal to the first gripping portion 32. The second hook portion 41 protrudes toward the third connecting shaft 53 when viewed in the axial direction of the first connecting shaft 51, and has a second gripping portion 42 that can press the second hook portion 41 toward the first hook portion 31, and a second convex portion 43 that holds the object to be lifted 200 further tip-side than the second gripping portion 42.

[0060] As a result, simply by gripping the first gripping portion 32 and the second gripping portion 42 of the hoisting device 100, the third link member 3 and the fourth link member 4 rotate. By simply gripping the first gripping portion 32 and the second gripping portion 42 with one hand, the hoisting device 100 can be moved from a position where the tips of the first hook portion 31 and the second hook portion 41 are separated to a position where they can be inserted into the insertion hole 201 of the object to be hoisted 200, or to a position where they can be removed. In addition, the hoisting device 100 can hold the object to be hoisted 200 by utilizing the weight of the object to be hoisted 200 with the first hook portion 31 of the third link member 3 and the second hook portion 41 of the fourth link member 4.

[0061] Furthermore, the hoisting device 100 can be inserted into and removed from the insertion hole 201 of the object to be lifted 200 while being held in one hand. The worker can move the hoisting device 100 with one hand and grasp the object to be lifted 200 with the other hand, or guide the hoisting device 100 into the insertion hole 201. This makes it easier to insert and remove the hoisting device 100 than when using both hands to insert a single hoisting device into the insertion hole 201 of the object to be lifted 200. Therefore, the operation of inserting and removing the hoisting device 100 from the object to be lifted 200 is not time-consuming. This allows the hoisting device 100 to be easily attached to and detached from the object to be lifted 200.

[0062] Furthermore, the third link member 3 and the fourth link member 4 may be rotatable to a position where either the first convex portion 33 or the second convex portion 43 entirely overlaps the other when viewed in the axial direction of the first connecting shaft 51.

[0063] This allows the first hook portion 31 and the second hook portion 41 of the sling device 100 to be moved to a position where the width between the first hook portion 31 and the second hook portion 41 in the direction perpendicular to the imaginary line VL is smallest when viewed in the axial direction of the first connecting shaft 51. This allows the third link member 3 and the fourth link member 4 of the sling device 100 to be rotated to a position where the sling device 100 can be removed from the insertion hole 201 simply by holding the first gripping portion 32 and the second gripping portion 42 with one hand.

[0064] Furthermore, when viewed in the axial direction of the first connecting shaft 51, the first gripping portion 32 protrudes further toward the second connecting shaft 52 than the first protrusion 33. When viewed in the axial direction of the first connecting shaft 51, the second gripping portion 42 protrudes further toward the third connecting shaft 53 than the second protrusion 43.

[0065] This prevents the lifting device 100 from being inserted into the insertion hole 201 of the object to be lifted 200 to a certain depth or more by the side surface of the first holding portion 32 facing the first convex portion 33 and the side surface of the second holding portion 42 facing the second convex portion 43.

[0066] The suspension device 100 is provided with a stopper that restricts the rotation of at least one of the first hook portion 31 and the second hook portion 41 relative to the first hook portion 31 when the first hook portion 31 and the second hook portion 41 are rotated around the fourth connecting shaft 54 as the rotation axis until one of the first protrusion portion 33 and the second protrusion portion 43 completely overlaps the other.

[0067] As a result, lifting tool 100 can be maintained in a state in which it can be easily inserted into insertion hole 201 of object to be lifted 200 simply by gripping first gripping portion 32 and second gripping portion 42.

[0068] Furthermore, sling device 100 may have elastic member 70 attached to second connecting shaft 52 and third connecting shaft 53, and biasing second connecting shaft 52 and third connecting shaft 53 in a direction that brings second connecting shaft 52 and third connecting shaft 53 closer to each other.

[0069] When the first gripping portion 32 and the second gripping portion 42 of the lifting device 100 are not gripped, the elastic force of the elastic member 70 causes the third link member 3 and the fourth link member 4 to rotate in a direction in which the tips of the first hook portion 31 and the second hook portion 41 move away from each other. Furthermore, when the gripping operation of the lifting device 100 is stopped after the first hook portion 31 and the second hook portion 41 are inserted into the insertion hole 201, the elastic force of the elastic member 70 presses the first hook portion 31 and the second hook portion 41 against the object to be lifted 200, even if the lifting device is not lifting the object. This allows the lifting device 100 to be connected to the object to be lifted 200 even when the worker is not gripping the object. The lifting device 100 can be easily attached to and detached from the object to be lifted, and a force to hold the object to be lifted can be applied to the object to be lifted by the lifting operation.

[0070] The above-described embodiment merely shows a typical form, and various modifications can be made without departing from the gist of one embodiment. Of course, the present invention can be embodied in various other forms, and the scope of the present invention is defined by the claims, and further includes the meaning of equivalents set forth in the claims, and all modifications within the scope of the claims.

[0071] In the above embodiment, an earth retaining material is given as an example of the lifted object 200. However, the lifted object 200 may be a material other than an earth retaining material. For example, it may be a construction material that is not an earth retaining material. The lifted object 200 is not limited to an earth retaining material.

[0072] In the above embodiment, the axial thickness of the first connecting shaft 51 of the first link member 1, the second link member 2, the third link member 3, and the fourth link member 4 is equal. However, the axial thickness of the first connecting shaft 51 of each member may be different.

[0073] In the above embodiment, the elastic member 70 is a tension spring. However, the elastic member 70 is not limited to a tension spring. The elastic member 70 may be any member that biases the second connecting shaft 52 and the third connecting shaft 53 in a direction that brings them closer together. For example, the elastic member 70 may be a rubber rod or a cylindrical elastic member.

[0074] In the above embodiment, the sling device 100 has the elastic members 70 attached to the second connecting shaft 52 and the third connecting shaft 53. However, the sling device 100 does not have to have the elastic members 70.

[0075] In the above embodiment, the elastic member 70 is attached to the second connecting shaft 52 and the third connecting shaft 53. However, the elastic member 70 may be attached to the first connecting shaft 51 and the fourth connecting shaft 54. In this case, the elastic member 70 biases the first connecting shaft 51 and the fourth connecting shaft 54 in a direction separating them.

[0076] In the above embodiment, the first grip portion 32 and the second grip portion 42 are gripped with fingers. However, the worker may grip the first grip portion 32 and the second grip portion 42 with a tool.

[0077] In the above embodiment, the sling device 100 has the first stopper 34 and the second stopper 44. However, the sling device 100 may have only one of the first stopper 34 and the second stopper 44. [Explanation of symbols]

[0078] 100 Lifting equipment 10 Link mechanism 1 First link member 2 Second link member 3 Third link member 31 First hook part 32 1st grip part 33 First convex part 34 First stopper 4 Fourth link member 41 Second hook part 42 Second grip part 43 Second convex part 44 Second stopper 51 1st connection shaft 52 2nd connection shaft 53 3rd connection shaft 54 4th connection shaft 60 Connecting member 60a Leg 70 Elastic member 200 Lifting object 201 Insertion hole 301 Wire VL Virtual Line A1 interval A2 spacing A3 Spacing A4 spacing L1 width L2 width

Claims

[Claim 1] A lifting tool that is attached to a lifting device and detached from an object to be lifted in order to lift the object, a connecting member attached to the lifting device; a first link member and a second link member, one end of which is rotatably supported on the connecting member by a first connecting shaft; a third link member having one end rotatably supported on the other end of the first link member by a second connecting shaft positioned parallel to the first connecting shaft; a fourth link member having one end rotatably supported on the other end of the second link member by a third connecting shaft positioned parallel to the first connecting shaft, the other end of the third link member and the other end of the fourth link member are rotatably connected by a fourth connecting shaft positioned parallel to the first connecting shaft, the third link member and the fourth link member are positioned so as to be line-symmetrical with each other with respect to a virtual line perpendicular to the axis of the first connecting shaft and the axis of the fourth connecting shaft, The third link member is a first hook portion at the other end of the first connecting shaft, the first hook portion being closer to the second connecting shaft than the imaginary line when viewed in the axial direction of the first connecting shaft when the second connecting shaft and the third connecting shaft are positioned on opposite sides of the imaginary line; The fourth link member is a second hook portion at the other end of the first connecting shaft, the second hook portion being closer to the third connecting shaft than the imaginary line when viewed in the axial direction of the first connecting shaft when the second connecting shaft and the third connecting shaft are positioned on opposite sides of the imaginary line; The first hook portion is a first gripping portion that protrudes toward the second connecting shaft as viewed in the axial direction of the first connecting shaft and is capable of pressing the first hook portion toward the second hook portion; and a first protrusion that holds the object to be lifted on a tip side of the first gripping portion, The second hook portion is a second gripping portion that projects toward the third connecting shaft as viewed in the axial direction of the first connecting shaft and is capable of pressing the second hook portion toward the first hook portion; and a second protrusion that holds the object to be lifted on a tip side of the second gripping portion, The third link member and the fourth link member are: the first connecting shaft is rotatable to a position where either the first convex portion or the second convex portion entirely overlaps the other convex portion, as viewed in the axial direction of the first connecting shaft; When the first hook portion and the second hook portion rotate about the fourth connecting shaft as a rotation axis at least until one of the first convex portion and the second convex portion entirely overlaps the other, The first gripping portion is When viewed in the axial direction of the first connecting shaft, the first connecting shaft protrudes toward the second connecting shaft more than the first protrusion, The second gripping portion is a sling that protrudes further toward the third connecting shaft than the second protrusion when viewed in the axial direction of the first connecting shaft.

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